Remove food all together, make resting cause partial respawns/ incounters that attack your camp, resting is only safe in inns and other havens.
Crude, but I would much rather have this than what we have now.
Resting too frequently could gradually increase the chances of being attacked. So if you try to play smart and rest as little as possible, the game should reward that. If you spam rest after every fight, you should have a much higher chance of being attacked. The game would teach the player the world is reactive and dangerous and rest spam would be discouraged quite naturally.
